Heat-conducting plate, especially for cooling or heating a building

ABSTRACT

A heat-conducting plate, in particular for cooling or heating a building. The heat-conducting plate including at least one layer of expanded graphite and a pipe which is at least partially received in the layer. The pipe is designed as a multi-layer composite pipe.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a US National Stage of International Application No.PCT/EP2013/069164, filed on Sep. 16, 2013, which claims the priority ofDE Application No. 20 2012 103540.5. filed on Sep. 17, 2012. Thecontents of each of the above-referenced applications is incorporatedherein by reference in its entirety.

FIELD OF INVENTION

The present invention relates to a heat-conducting plate, in particularfor cooling or heating a building, comprising at least one layer ofexpanded graphite and a pipe which is at least partially received in thelayer.

BACKGROUND

Heat-conducting plates of the type mentioned in the introduction areknown from the prior art. By way of example, European patent EP 1 512933 A2 describes heat-conducting plates made of expanded graphitewithout binder with preferred heat conduction parallel to the platesurface. Furthermore, said document describes a method for producing theheat-conducting plates. In this case, completely expanded graphite iscompacted under the directional action of a pressure, such that layerplanes of the graphite are preferably arranged perpendicular to theaction of the pressure, with individual aggregates of the graphitehooking up with one another. It is thereby possible to produceself-supporting heat-conducting plates having a thickness, for example,of 8 to 50 mm.

Heat-conducting plates of this type are used, for example, as wall,floor or ceiling elements for heating or cooling a room. For thispurpose, the heat-conducting plate can be used, for example, inconjunction with heating systems which utilize a fluid heat transfermedium. Pipes made of metal, for example copper, or plastic areintroduced into the heat-conducting plates for the transportation of afluid heat transfer medium, for example water. The pipes in this respectare generally arranged in a helical or meandering manner. As analternative, the pipes can also be placed between two heat-conductingplates, which are then pressed together.

When using plastic pipes, it proves to be a disadvantage that restoringforces of the pipe arise during the production of the heat-conductingplate, for example when the pipes are arranged in a helical ormeandering manner in a heat-conducting plate. This is because the pipesarranged in the expanded graphite readily undergo elastic deformationduring the production as a result of the action of pressure. Theserestoring forces can lead to damage to the heat-conducting plateparticularly in the case of relatively thin heat-conducting plates.Furthermore, it is possible that the plastic pipes may come loose andbecome separated on account of these restoring forces if they are notcompletely embedded in the heat-conducting plate. In addition, thepressing of a plastic pipe into a heat-conducting plate or the pressingtogether of two heat-conducting plates with a plastic pipe arrangedtherebetween may cause damage to the plastic pipe itself.

The use of copper pipes is very expensive and, on account of the highdead weight, leads to heavy heat-conducting plates. Furthermore,corrosive damage can arise on the copper pipe under certain conditions.By way of example, the presence of condensed water and at least onefurther metal, e.g. aluminum, can form a galvanic cell on account of thedifferent electrochemical potentials of the metals, and this leads togalvanic corrosion of the copper pipe. This can lead, for example, toleaks or to undesirable discolorations of the copper pipe.

SUMMARY

It is an object of the invention to present a solution which avoids theaforementioned disadvantages.

Said object is achieved according to the invention by a heat-conductingplate, in particular for cooling or heating a building, which comprisesat least one layer of expanded graphite and a pipe which is at leastpartially received in the layer. The pipe which is at least partiallyreceived in the layer is in this case designed as a multi-layercomposite pipe.

The use of a multi-layer composite pipe prevents restoring forces fromarising during the production of the heat-conducting plate, for examplewhen the multi-layer composite pipe is arranged in a helical ormeandering manner. A multi-layer composite pipe bent or shaped accordingto the desired arrangement essentially does not alter its shape or itsposition. If the multi-layer composite pipe should be bent or deformedduring the production process, it undergoes plastic deformation and nohigh restoring forces arise. Damage to the layer of the heat-conductingplate or separation from the layer is therefore not possible. Incontrast to a pure plastic pipe, the multi-layer composite pipe hasgreater stability and thereby contributes to the stability of the entireheat-conducting plate. In contrast to copper pipes, multi-layercomposite pipes have a considerably lower weight and are not susceptibleto corrosion, in particular in the region of the outer side of the pipe,in the presence of a second metal. In addition, it is possible to reducethe production costs of a heat-conducting plate according to theinvention considerably compared to a heat-conducting plate comprisingcopper pipes.

According to an advantageous configuration of the invention, themulti-layer composite pipe has an inner plastic layer, anadhesion-promoting layer and an outer metal layer. A multi-layercomposite pipe of this type is distinguished by its low weight combinedwith good heat conduction.

According to a further advantageous configuration of the invention, themulti-layer composite pipe has an inner plastic layer, anadhesion-promoting layer, a metal layer, a further adhesion-promotinglayer and an outer plastic layer. A multi-layer composite pipe of thistype is distinguished by its high stability and flexural rigidity.

According to a further advantageous configuration of the invention, atleast one surface of the heat-conducting plate is perforated or hastextures. When a heat-conducting plate of this type is used in abuilding, for example, it is thereby possible to improve the acousticproperties of the heat-conducting plate, in particular the soundabsorption.

According to a further advantageous configuration of the invention, atleast one surface of the heat-conducting plate has a layer of mineralwool. It is thereby likewise possible to improve the acoustic propertiesof the heat-conducting plate.

According to a further advantageous configuration of the invention, theheat-conducting plate is provided with apparatuses for attachment tofurther heat-conducting plates or other elements, in particular wall andceiling surfaces. A heat-conducting plate can thereby be attached to aceiling surface of a room in a suspended manner, for example.

According to a further advantageous configuration of the invention, theheat-conducting plate is produced by pressing the expanded graphite withthe inserted multi-layer composite pipe.

According to a further advantageous configuration of the invention, theheat-conducting plate is produced by pressing the multi-layer compositepipe into recesses in the layer of expanded graphite.

According to a further advantageous configuration of the invention, theheat-conducting plate has a further layer of expanded graphite and isproduced by pressing the two layers with the multi-layer composite pipearranged therebetween.

According to a further advantageous configuration of the invention, theheat-conducting plate comprises additives, in particular syntheticresin.

Further advantageous configurations of the invention are disclosed inthe following detailed description of exemplary embodiments and also thedependent patent claims.

Hereinbelow, the invention will be described on the basis of theexemplary embodiments with reference to the accompanying figures. In thefigures, identical components from different exemplary embodiments areprovided with identical reference signs and are not describedrepeatedly.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a schematic cross section of a heat-conducting plateaccording to a first exemplary embodiment of the invention,

FIG. 2 shows a schematic cross section of a heat-conducting plateaccording to a second exemplary embodiment of the invention,

FIG. 3 shows a schematic cross section of a heat-conducting plateaccording to a third exemplary embodiment of the invention,

FIG. 4 shows a schematic plan view of a heat-conducting plate accordingto a fourth exemplary embodiment of the invention,

FIG. 5 shows a schematic cross section of a heat-conducting plate in theevent that a multi-layer composite pipe is pressed in, according to afifth exemplary embodiment of the invention, and

FIG. 6 shows a schematic cross section of a heat-conducting plate in theevent that two layers and a multi-layer composite pipe are pressed,according to a sixth exemplary embodiment of the invention.

DETAILED DESCRIPTION

FIG. 1 shows a schematic cross section of a heat-conducting plate 1according to a first exemplary embodiment of the invention. Theheat-conducting plate 1 has a layer 2 of expanded graphite. Furthermore,the heat-conducting plate 1 has a multi-layer composite pipe 3, which isintroduced into the layer 2 partially on a surface 4.

The multi-layer composite pipe 3 has an inner plastic layer 5, forexample of crosslinked polyethylene (PE-X). Alternatively, the innerplastic layer 5 can also consist of a polyethylene material for anincreased temperature resistance (PE-RT). Moreover, the multi-layercomposite pipe 3 has an adhesion-promoting layer 6. Theadhesion-promoting layer 6 bonds the inner plastic layer 5 to an outermetal layer 7. By way of example, the outer metal layer 7 can beproduced from an aluminum material or an aluminum alloy.

A heat-carrying fluid, for example water, flows inside the multi-layercomposite pipe 3, in order to emit heat to the layer 2 or in order toabsorb heat from the layer 2.

The heat-conducting plate 1 is produced by placing the multi-layercomposite pipe 3 into expanded graphite and subsequent pressing. Theaction of directional pressure forms the layer 2 of expanded graphite,into which the multi-layer composite pipe 3 is at least partiallyembedded, such that there is a force-fitting and/or form-fittingconnection between the layer 2 and the multi-layer composite pipe 3.

Alternatively, the heat-conducting plate 1 can comprise additives, inparticular synthetic resin, in order for example to increase thestability of the heat-conducting plate 1. In this case, the additivescan be admixed to the expanded graphite during the production of thelayer 2 or can be attached to the layer 2 or applied theretosubsequently, for example as an additional layer.

The heat-conducting plate 1 is suitable, for example, for use in abuilding for cooling or heating rooms. It is preferable for theheat-conducting plate to be suspended on a ceiling of a room. In thiscase, the heat-conducting plate 1 absorbs heat from the ambient airwhich surrounds it via the layer 2, for example, and emits this heat tothe fluid inside the multi-layer composite pipe 3 for cooling the room.Conversely, thermal energy of the fluid is emitted via the multi-layercomposite pipe 3 to the layer 2, which in turn emits the heat to theambient air which surrounds it for heating the room, in particular byradiation.

FIG. 2 shows a schematic cross section of a heat-conducting plate 1according to a second exemplary embodiment of the invention. Theheat-conducting plate 1 has a multi-layer composite pipe 3, which isformed by five layers. The multi-layer composite pipe 3 has an innerplastic layer 5, an adhesion-promoting layer 6, a metal layer 7, asecond adhesion-promoting layer 8 and a second, outer plastic layer 9.The multi-layer composite pipe 3 is arranged within the layer 2 in sucha manner that a pipe outer side 10 of the multi-layer composite pipe 3terminates flush with the surface 4 of the layer 2.

The inner plastic layer 5 and also the second, outer plastic layer 9 canconsist, for example, of crosslinked polyethylene (PE-X) or of apolyethylene material for an increased temperature resistance (PE-RT).The metal layer 7 can be produced from an aluminum material or analuminum alloy.

Compared to the configuration shown in FIG. 1, the multi-layer compositepipe 3 has a higher stability or rigidity combined with a low deadweight.

The arrangement of the multi-layer composite pipe 3 flush with thesurface 4 ensures a good transfer of heat between the layer 2 and themulti-layer composite pipe 3. This is primarily because the heatconduction within the layer 2 is better parallel to the surface 4 thanperpendicular to the surface 4 of the layer 2 on account of the factthat the layer 2 is produced under directional pressure.

In an embodiment of the heat-conducting plate 1 which is not shown, atleast one outer side of the layer 2 may be perforated or have textures.It is thereby possible for acoustic properties of the heat-conductingplate 1 to be improved. By way of example, depressions can be made onsuch an outer side of the heat-conducting plate 1.

FIG. 3 shows a schematic cross section of a heat-conducting plate 1according to a third exemplary embodiment of the invention. Here, theheat-conducting plate 1 is configured in a manner correspondingsubstantially to the second exemplary embodiment shown in FIG. 2. Incontrast to the configuration shown in FIG. 2, however, the multi-layercomposite pipe 3 is arranged within the layer 2 in such a manner that itis spaced apart from a surface 4 and a bottom side 11 of the layer 2. Inaddition, the heat-conducting plate 1 has a layer of mineral wool 12 onthe surface 4 of the layer 2. Moreover, holes 21, in particular bores,are provided in the layer 2. It is thereby possible in conjunction withthe mineral wool 12 to achieve a sound absorption effect, for example.By way of example, the layer of mineral wool 12 can also be arranged onanother outer side or a plurality of outer sides of the layer 2.

Alternatively, however, it is also possible for other layers, forexample plastic layers or metal layers, to be attached to one or moreouter sides of the layer 2, in order for example to protect theheat-conducting plate 1 against mechanical or other environmentalinfluences.

FIG. 4 shows a schematic plan view of a heat-conducting plate 1according to the invention with a multi-layer composite pipe 3 embeddedtherein. The heat-conducting plate 1 has a first connection 13 and asecond connection 14. The connection 13 and the connection 14 areconnected via a multi-layer composite pipe 3 as per a configuration onthe basis of FIGS. 1 to 3. Here, the multi-layer composite pipe 3 isarranged within the layer 2 in a meandering manner. Moreover, theheat-conducting plate 1 has two holding apparatuses 15 for attaching theheat-conducting plate 1 to wall or ceiling surfaces. In addition, themulti-layer composite pipe 3 has a plurality of bend regions 16.

By way of example, the holding apparatuses 15 can have nails, brackets,hooks or anchors, in order to attach the heat-conducting plate 1 to aceiling surface of a room.

By way of example, essentially no restoring forces arise in the bendregions 16 during the production of the heat-conducting plate 1 byvirtue of the use of the multi-layer composite pipe 3, since themulti-layer composite pipe 3 can be plastically shaped beforehand by themetal layer 7.

The heat-conducting plate 1 is connected, for example, to a heatingsystem, with a fluid, for example water, entering into the multi-layercomposite pipe 3 via the connection 13. In accordance with thearrangement of the multi-layer composite pipe 3, the fluid isdistributed over the surface area of the layer 2. The fluid flows awayagain via the connection 14.

A heat-conducting plate 1 of this type is suitable in particular for usein buildings for cooling or heating a room. Heat-conducting plates ofthis type are preferably fastened to ceilings of a room. It proves to beparticularly advantageous that the heat-conducting plate 1 has aconsiderably lower dead weight compared to heat-conducting plates havingcopper pipes on account of the low weight of the multi-layer compositepipe 3. It is thereby possible for heat-conducting plates of this typeto also be attached to ceilings of buildings with a smaller load-bearingcapacity, for example old buildings. Moreover, it is possible to producecomparatively thin heat-conducting plates, because the multi-layercomposite pipe 3 contributes to the stability of the layer 2 of expandedgraphite above all on account of the metal layer 7.

The connections 13 and 14 of the heat-conducting plate 1 which are shownin FIG. 4 can be arranged in a different manner on the layer 2, forexample lying opposite one another. In addition, the multi-layercomposite pipe 3 can also run differently within the layer 2, forexample in a helical manner. Moreover, it is conceivable for a pluralityof multi-layer composite pipes 3 to be arranged within a layer 2, thesebeing connected to a heating system, for example, via the connections 13and 14 and/or further connections.

What is shown in a fifth exemplary embodiment of the invention as perFIG. 5 is a schematic cross section of a heat-conducting plate 1 in theevent that a multi-layer composite pipe 3 is pressed in. The layer 2which has already formed under the action of pressure has a recess 17,this having been made in a post-machining step, for example. The recess17 is matched to an external diameter and the arrangement or shape ofthe multi-layer composite pipe 3 in such a manner that the multi-layercomposite pipe 3 can be pressed, pushed or placed into the recess 17.

By way of example, the recess 17 can be configured in such a manner thata multi-layer composite pipe 3 arranged in a meandering manner as perthe configuration shown in FIG. 4 can be introduced into the layer 2.

FIG. 6 shows a schematic cross section of a heat-conducting plate 1 tobe pressed according to a sixth exemplary embodiment of the invention.In addition to the layer 2, the heat-conducting plate 1 has a secondlayer 18 of expanded graphite which has already formed under the actionof pressure. The multi-layer composite pipe 3 is placed between the twolayers 2 and 18. The heat-conducting plate 1 is produced by pressing thetwo layers 2 and 18, for example under the action of pressure as per thearrow directions 19 and 20. A force-fitting and/or form-fittingconnection is established between the two layers 2 and 18 and also themulti-layer composite pipe 3.

The features of a heat-conducting plate which have been presented in theexemplary embodiments described can be combined with one another invarious ways in order to realize the respectively mentioned advantagesand/or functions.

LIST OF REFERENCE SIGNS

-   1 Heat-conducting plate-   2 Layer-   3 Multi-layer composite pipe-   4 Surface-   5 Plastic layer-   6 Adhesion-promoting layer-   7 Metal layer-   8 Adhesion-promoting layer-   9 Plastic layer-   10 Pipe outer side-   11 Bottom side-   12 Mineral wool-   13 Connection-   14 Connection-   15 Holding apparatus-   16 Bend region-   17 Recess-   18 Layer-   19 Arrow direction-   20 Arrow direction-   21 Hole

1. A heat-conducting plate for cooling or heating a building, comprisingat least one layer of expanded graphite and a pipe which is at leastpartially received in the layer, wherein the pipe is designed as amulti-layer composite pipe.
 2. The heat-conducting plate according toclaim 1, in which the multi-layer composite pipe has an inner plasticlayer, an adhesion-promoting layer and an outer metal layer.
 3. Theheat-conducting plate according to claim 1, in which the multi-layercomposite pipe has an inner plastic layer, an adhesion-promoting layer,a metal layer, a further adhesion-promoting layer and an outer plasticlayer.
 4. The heat-conducting plate according to claim 2, in which theinner plastic layer and/or the outer plastic layer are formedessentially from polyethylene (PE) and the metal layer is formedessentially from an aluminum material.
 5. The heat-conducting plateaccording to one-of claim 1, in which at least one surface is perforatedor has textures.
 6. The heat-conducting plate according to claim 1, inwhich at least one surface has a layer of mineral wool.
 7. Theheat-conducting plate according to claim 1, in which provision is madeof holding apparatuses for attachment to further heat-conducting platesor other elements, including wall and ceiling surfaces.
 8. Theheat-conducting plate according to claim 1, which is produced bypressing the expanded graphite with the inserted multi-layer compositepipe.
 9. The heat-conducting plate according to claim 1, which isproduced by pressing the multi-layer composite pipe into recesses in thelayer.
 10. The heat-conducting plate according to claim 1, which has afurther layer of expanded graphite and is produced by pressing the twolayers with the multi-layer composite pipe arranged therebetween. 11.The heat-conducting plate according to claim 1, which comprisesadditives, including synthetic resin.